Acetylene gas lamps were used to illuminate buildings, as lighthouse beacons, and as headlights on motor-cars and bicycles. Portable carbide lamps, worn on the hat or carried by hand, were widely used in mining in the early twentieth century. They are still employed by cavers, hunters, and cataphiles.
The conventional process of producing acetylene in a lamp involves putting the calcium carbide in the lower chamber (the generator). The upper reservoir is then filled with water. A threaded valve or other mechanism is used to control the rate at which the water is allowed to drip into the chamber containing the calcium carbide. By controlling the rate of water flow, the production of acetylene gas is controlled. This, in turn, controls the flow rate of the gas and the size of the flame at the burner, (and thus the amount of light it produces).
This type of lamp generally has a reflector behind the flame to help project the light forward. An acetylene gas powered lamp produces a surprisingly bright, broad light. Many cavers prefer this type of unfocused light as it improves peripheral vision in the complete dark. The reaction of carbide with water produces a fair amount of heat independent of the flame. In cold caves, carbide lamp users can use this heat to help stave off hypothermia.
When all of the carbide in a lamp has been reacted, the carbide chamber contains a wet paste of slaked lime (calcium hydroxide). This is emptied into a waste bag and the chamber can be refilled.
Small carbide lamps called "carbide candles" are used for blackening rifle sights to reduce glare. These "candles" are used due to the sooty flame produced by acetylene.
In 1892, Thomas Willson discovered an economically efficient process for creating calcium carbide in an electric arc furnace from a mixture of lime and coke. The arc furnace provides the high temperature required to drive the reaction. Manufacture of calcium carbide was an important part of the industrial revolution in chemistry, and was made possible in the USA as a result of massive amounts of inexpensive hydroelectric power produced at Niagara Falls before the turn of the 20th century.
In 1895, Willson sold his patent to Union Carbide. Domestic lighting with acetylene gas was introduced circa 1894 and bicycle lamps from 1896.
The first carbide mining lamp developed in the United States was patented in New York on August 28, 1900 by Frederick Baldwin. Another early lamp design is shown in a patent from Duluth, Minnesota on October 21, 1902. In the early 1900s, Gustaf Dalén invented the Dalén light. This combined two of Dalén's previous inventions: the substrate Agamassan and the Sun valve. Inventions and improvements to carbide lamps continued for decades. On March 10, 1925 Andrew Prader of Spokane, Washington was granted a United States Patent, number 1,528,848 for certain new and useful improvements for Acetylene Lamps.
After carbide lamps were implicated in an Illinois coal-seam methane gas explosion that killed 54 miners, the 1932 Moweaqua Coal Mine disaster, carbide lamps were less used in United States coal mines. They continued in use in the coal pits of other countries, notably Russia and Ukraine.
Lighting systems 
Carbide lighting was used in rural and urban areas of the United States which were not served by electrification. Its use began shortly after 1900 and continued past 1950. Calcium carbide pellets were placed in a container outside the home, with water piped to the container and allowed to drip on the pellets creating a gas. This gas was piped to lighting fixtures inside the house, where it was burned, creating a very bright flame. Carbide lighting was inexpensive but was prone to gas leaks and explosions.
Acetylene lamps were also used on riverboats for night navigation. The National Museum of Australia has a lamp made in about 1910 that was used on board PS Enterprise, a paddle steamer which has been restored to working order and is also in the museum's collection.
They are also used for night hunting in some African countries.
Use in caving 
Early caving enthusiasts, not yet having the advantage of light-weight electrical illumination, introduced the carbide lamp to their hobby. While increasingly replaced by more modern choices, a substantial percentage of cavers still use this method.
In cave surveys, carbide lamps are favoured for the lead or "point" surveyor, who must identify suitable points in the cave to designate as survey stations. The sooty carbide flame may be used to harmlessly mark cave walls with a nontoxic and removable station label. Especially favoured for this purpose are all-brass lamps or lamps made with no ferromagnetic metals, as these lamps do not deflect the needles of a magnetic compass, which is typically read while brightly illuminated from above using the caver's lamp.
Apart from their use as cave surveying tools, many cavers favour carbide lamps for their durability and quality of illumination. They were once favoured for their relative illumination per mass of fuel compared to battery powered devices, but this advantage was largely negated with the advent of high-intensity LED illumination.
The acetylene producing reaction is exothermic, which means that the lamp's reactor vessel will become quite warm to the touch; this can be used to warm the hands. The heat from the flame can also be used to warm the body by allowing the exhaust gases to flow under a shirt pulled out from the body: such a configuration is referred to as a "Palmer furnace", after geologist Arthur Palmer.
See also 
- Clemmer, Gregg. American Miners' Carbide Lamps: A Collectors Guide to American Carbide Mine Lighting. Westernlore Publications, 1987.
- Thorpe, David. "Carbide Light: the Last Flame in American Mines." Bergamot Books, 2006. ISBN 0-9760905-2-X
- Thorpe, David. "Beneath the Surface: Inventors and Marketeers of the Miners' Carbide Light." Bergamot Books, 2010. ISBN 0-9760905-6-2
- Pohs, Henry. "The Miners Flame Light Book" Flame Publishing, 1995. ISBN 0-9641165-0-2
- Card, Peter W. (October 2004). Early Vehicle Lighting. Shire Publications. ISBN 978-0-7478-0585-4.
|Wikimedia Commons has media related to: Carbide lamps|
- acethylene.com A comprehensive guide to the care and maintenance of acetylene gas lamps
- A User's Guide to Carbide Cap Lamps. Has many good pictures & videos.
- Carbide lamp Demonstration experiment: Instruction and video
- The Carbide Caver A website on the history, restoration, and use of carbide lamps for caving.